fix(cardano-blockchain-types): time_to_slot calculation

Signed-off-by: bkioshn <[email protected]>

Author: bkioshn

rust/cardano-blockchain-types/src/network.rs

@@ -185,16 +185,25 @@ impl Network {
             return None;
         }
 
-        let elapsed_slots = if time < shelley_start_time {
+        let (elapsed_slots, era_known_slot) = if time < shelley_start_time {
             // Byron era
             let time_diff = time - byron_start_time;
-            time_diff.num_seconds() / i64::from(genesis.byron_slot_length)
+            (
+                time_diff.num_seconds() / i64::from(genesis.byron_slot_length),
+                genesis.byron_known_slot,
+            )
         } else {
             // Shelley era
             let time_diff = time - shelley_start_time;
-            time_diff.num_seconds() / i64::from(genesis.shelley_slot_length)
+            (
+                time_diff.num_seconds() / i64::from(genesis.shelley_slot_length),
+                genesis.shelley_known_slot,
+            )
         };
-        Some(Slot::from_saturating(elapsed_slots))
+
+        let era_known_slot = i64::try_from(era_known_slot).ok()?;
+
+        Some(Slot::from_saturating(elapsed_slots + era_known_slot))
     }
 }